As disclosed by Thomas, et al., in U.S. Pat. No. 5,481,294, which is assigned to the same assignee as the present invention and the disclosure of which is herein incorporated by reference, the signal (e.g., television or radio), that has been selected, and is being viewed or heard, by an audience member on a television or radio receiver in a statistically selected household, may be determined by ascertaining the channel to which the tuner of the television or radio is tuned. This channel information is stored locally for subsequent retrieval by a central data collection office. The central data collection office matches the retrieved channel information against a cable/station record which indicates which station corresponds to which channel and/or against a program record list of television or radio programs which were transmitted on that channel in order to determine the television or radio program that the audience member selected. As noted in U.S. Pat. No. 5,481,294 by Thomas, et al., this process becomes cumbersome as the number of signal sources, the number of channels, the changes to channel mappings at a cable headend, and/or the number of television or radio programs increase, and can fail to produce usable data if there is an error in the program record list that provides the concordance between channels and programs.
Several approaches have been proposed that are intended to avoid the cumbersome cable/station record and/or program record list manner of keeping track of which station and/or which programming is available from which signal source and channel within a sampled household. As an example, one such approach to measuring the usage of electronic entertainment equipment (commonly called “tuning” data) involves the addition of an identifying code to a radio or television program, the distribution of the identifying code with the program throughout the relevant broadcasting system, the detection and interpretation of the identifying code when the broadcast signal is viewed or heard in a statistically selected monitoring site, and using the identifying (or ancillary) code to identify the program to which the television or radio was tuned. An example of a system which implements this type of measurement approach may be found in the following patents: U.S. Pat. No. 5,481,294 to Thomas, et al., who describe, inter alia, identifying codes added to the vertical blanking interval of an NTSC television broadcast; U.S. Pat. No. 5,629,739 to Dougherty, who is particularly concerned with the addition of an identifying code to a low energy portion of the audio spectrum of an NTSC signal; and U.S. Pat. No. 5,404,377 to Moses, who teaches an audio encoding arrangement using signal masking to decrease the perceptibility of the identifying code. The disclosures of U.S. Pat. No. 5,481,294, U.S. Pat. No. 5,629,739, and U.S. Pat. No. 5,404,377 are herein incorporated by reference.
As another example, a program signature is extracted from the program signal selected for use (e.g., for viewing if the signal is a television signal or for listening if the signal is a radio signal) in the sampled household and is later compared to previously extracted reference signatures in an effort to match the program signature to a previously extracted reference signature in order to thereby identify the selected program. Accordingly, this signature approach is a correlation system which uses a sample frequency that is less than the frequency of the program signal. For example, such an approach to measuring usage of electronic entertainment equipment involves the extraction of a characteristic feature signature (or characteristic feature signature set) from the programming selected for viewing and the storing of a time-stamped signature (or signature set) in a memory for subsequent transmission to a central data collection office where the signature (or signature set) is compared with corresponding reference signatures collected by the central office from known broadcasting sources. This approach is taught by Lert and Lu in U.S. Pat. No. 4,677,466. The teaching of U.S. Pat. No. 4,677,466 is herein incorporated by reference.
Such monitoring equipment in the sampled household also stores a time stamp in addition to the ancillary code or program signature. The time stamp is used to determine the time and date of viewing and/or listening relative to the selected program.
Yet another approach to the measurement of the usage of electronic entertainment equipment has been that of comparing the viewed signal (or some component or artifact thereof) with all the signals available to a sampled household at the time the measurement is made. A review of apparatus and methods useful for this measurement approach is found in the teachings of Thomas, et al. in U.S. Pat. No. 5,629,739 and of Lu, et al. in U.S. Pat. No. 5,594,934. The teachings in U.S. Pat. No. 5,594,934 and in U.S. Pat. No. 5,629,739 are herein incorporated by reference.
Chan, in U.S. application Ser. No. 08/654,309, filed on May 28, 1996, teaches a sensor arrangement for non-intrusively obtaining a representation of video and synchronization signals from a television receiver. The disclosure of the aforementioned U.S. application Ser. No. 08/654,309 is herein incorporated by reference.
Thomas, et al., in U.S. Pat. No. 5,425,100 and U.S. Pat. No. 5,526,427, both of which are assigned to the same assignee as the present invention, teach a hierarchical, multi-level encoding system for identifying a transmitted program by reading an ancillary program identifying code which is sequentially added to the program as it passes through various stages of a program distribution network. The disclosures of U.S. Pat. No. 5,425,100 and U.S. Pat. No. 5,526,427 are hereby incorporated by reference. Other program monitoring systems employing ancillary codes which are embedded in a transmitted program are taught by Haselwood, et al. in U.S. Pat. No. 4,025,851 and by Crosby in U.S. Pat. No. 3,845,391.
A program monitoring system that exclusively relies on ancillary codes may produce inaccurate results when ancillary codes are either intentionally or accidentally omitted from program signals. Even when the original program signal is encoded with an ancillary code, there is a risk that the ancillary code will be intentionally removed before the program signal is viewed or heard. There is also the risk that ancillary codes may be accidentally removed before the program in which they are embedded is viewed or heard. For example, ancillary codes that are embedded in video or audio program signals so that they are undetectable to a viewer or listener, or so that they are at least unobtrusive enough to be no more than minimally detectable by a viewer or listener, are commonly stripped from the video or audio program signals when the video or audio program signals are compressed (e.g., such as by the MPEG II compression scheme used with digital television signals).
Moreover, ancillary codes, which are inserted into vertical blanking intervals (VBI) of the video portions of program signals, and which survive passage through the signal transmission chain so as to be received by a user's television receiver, are commonly removed from the video before the video is applied to the CRT of a television. As a result, non-intrusive acquisition of these VBI ancillary codes is impractical because such non-intrusive acquisition usually requires the use of probes which generally pick up the video sent by the tuner to the CRT after the VBI ancillary codes have already been stripped from the video.
Therefore, ancillary codes in the vertical blanking interval are more easily detected if the monitored television receiver is opened so that leads of the monitoring equipment can be soldered to video test points of the television receiver at which the ancillary codes are still present. However, such an arrangement is intrusive, leading to objections by the members of the statistically sampled households.
Signal comparison program monitoring systems, other than signature matching systems such as those described above, have also been used in order to determine the signal sources (e.g., channels) of the programs being viewed or heard. One of the oldest known signal comparison program monitoring system compares a synchronization component of a television program signal selected by a television tuner with a corresponding synchronization component in a program signal selected by a reference tuner. This signal comparison program monitoring system credits viewing to the signal source selected by the reference tuner when and if the two synchronization components match within some predetermined error.
Currey, in U.S. Pat. No. 3,372,233, provided an early teaching of such a program monitoring system which compared the phasing of vertical synchronization signals for this purpose. Currey's approach was not particularly successful because the vertical synchronization components from different signal sources occasionally match. When this type of matching occurs, the program source measurement is ambiguous. Solar, in U.S. Pat. No. 4,764,808, and Gall, in U.S. Pat. No. 4,847,685, provided improved synchronization component measurement systems that did not entirely overcome the basic shortcoming of the Currey approach. In U.S. Pat. No. 5,294,977, Fisher, et al. disclosed a synchronization component based measurement system operating in a restricted environment in which such phase coincidences can be avoided.
Another signal comparison program monitoring system correlates a receiver signal, which may be extracted from a receiver being monitored, with a reference signal, which may be supplied by a reference tuner that is tuned consecutively to the possible program signal sources to which the monitored receiver may be tuned. This correlation system determines the channel being viewed or heard when the correlation between the receiver signal from the monitored receiver and the reference signal from the reference tuner exceeds some predetermined value. This monitoring approach was initially adapted for the purpose of in-home identification of viewed television programs by Kiewit, et al. in U.S. Pat. No. 4,697,209, the disclosure of which is herein incorporated by reference. The teachings of Kiewit, et al. have been expanded upon by Thomas, et al., in U.S. Pat. No. 5,481,294, who described the use of signatures extracted from either a video component or an audio component of a receiver signal, and who discussed the operational advantages of using non-invasive sensors to acquire the components.
A further comparison program monitoring system was placed in commercial service in 1984 by the A. C. Nielsen Company and was internally referred to as the Real Time Correlation (RTC) system. The RTC system used a combination of vertical synchronization component matching and audio correlation to identify an unknown signal. The RTC system did so by first making a preliminary identification based upon matching of vertical synchronization components. However, this preliminary identification would not be unique if the unknown transmitted signal, for example, was one of several sync-locked signals originating at a local cable head-end. Therefore, the RTC system resolved ambiguities by correlating the audio component of the selected transmitted signal from the monitored television with the audio component of the reference signal from the reference tuner whose synchronization component matched the synchronization component of the transmitted signal.
Correlation program monitoring systems are generally more robust and less affected by signal degradation than are code reading program monitoring systems. Even so, a signal correlation program monitoring system, which compares two signals (e.g., a receiver signal selected by a monitored television at a television viewing site in a statistically sampled household, and a reference signal selected by a reference tuner at a different local reference site), works best when the two signals to be correlated are both high quality replicas of what was actually transmitted. If one of the correlated signals, such as the receiver signal selected by the monitored television, is acquired by a non-intrusive sensor at the television viewing site, and if the other correlated signal, such as the reference signal selected by the reference tuner, is acquired from the audio or video circuitry of a tuner at a different local reference site, artifacts introduced by the non-intrusive measurement at the television viewing site may have a substantial adverse impact on the correlation between the receiver and reference signals. To reduce such artifacts, Thomas, et al., in the aforementioned U.S. Pat. No. 5,481,294, teach the suppression or removal of background noise from an audio signal acquired by a non-intrusive microphone at the receiver viewing or listening site.
Another problem facing signal correlation systems is that, because signal correlation systems require an on-going collection of reference signatures by equipment dedicated to monitoring the signals transmitted from each program signal source in whatever regional market is being measured, the operating cost of a signature-based program monitoring system is generally higher than that of a comparable program monitoring system relying on ancillary codes.
A problem facing all, or nearly all, program monitoring systems arises from signal sources which originate within the household itself. Signal sources of this sort may include computers or video games, which use the monitored television's display, and video cassette (or tape) recorders, which play program signals that were recorded at earlier times or that are recorded on rental cassettes (or tapes). The use of such local signal sources is, with one exception to be discussed below, systematically excluded from a long-established audience measurement parameter called “Households Using Television” (HUT) because the use of a television receiver with a locally generated signal does not fall within the scope of conventional television audience measurements.
Moreover, if a local signal source is not identified as such, a program monitoring system could either (i) erroneously count viewing or listening based on this local signal source as it would count viewing or listening based upon a remote signal source, or (ii) label the viewing or listening based on the local signal source as an unidentified activity. Either way, viewing or listening based upon a local signal source would be included as contributions to the overall HUT value reported by the program monitoring system in such a way as to create ambiguities.
The exception mentioned above relates to recording of programs by VCRs for later time shifted viewing. The reportable HUT value generally counts time-shifting viewing either at the time of recording or at the time of playback, but does not count at both recording and playback. By not counting at both recording and playback, double counting is avoided. Also, whether counting is done at the time of recording or at the time of playback, program monitoring systems strive to count only transmitted programs and seek to avoid counting non-transmitted programs, such as rented movies.
Also, a VCR typically has a number of modes in a non-record mode. For example, in a monitor mode, the VCR is used to pass through a currently selected transmitted program signal so that the signal may be viewed on a television, but the VCR does not concurrently record the signal. In a tune/record mode, the VCR is used to pass through a currently selected transmitted program signal for both viewing and recording. In a non-tune/record mode, the VCR is used to record a program without concurrent viewing of the program on a television; thus, the program is recorded for time-shifted playing. In a play mode, the VCR is used to play transmitted materials, such as time-shifted recordings, and non-transmitted materials, such as rented movies. In an off mode, the VCR is off. Because of this number of modes, a VCR presents one of the most difficult program monitoring challenges.
Early measurements of VCRs in sampled households involved monitoring of both the control switches and the tuners of VCRs. This monitoring resulted in the measurement of recording, which was credited to program ratings when recorded, and in the identification of all other uses as not contributing to program ratings. Thus, for example, when recording was counted as HUT viewing, all play activity was counted as non-HUT usage. These early measurements of VCRs involved a complicated and expensive disassembly and modification of consumers' equipment in order to physically connect switch monitoring equipment to the VCR switches.
Subsequent improvements in VCR measurement provided less invasive, and in some cases entirely non-invasive, ways of acquiring the requisite signals. In U.S. Pat. No. 4,633,302, Damoci teaches a method of picking up an artifact from the output of a VCR's erase-head in order to ascertain that the measured VCR is recording a tuned signal. Vitt, et al., in U.S. Pat. No. 5,165,069, teach a further improved measurement method in which all the status information (including a sensed erase-head output, which is commonly selected by different manufacturers to be a continuous wave (CW) tone lying between thirty and seventy-five KHz) is acquired from a sensor or pickup located immediately adjacent to, but externally of, the VCR's housing. The disclosure of Vitt, et al. is herein incorporated by reference. Mostafa, et al., in U.S. Pat. No. 5,495,282, teach yet another non-invasive arrangement for monitoring the operation of a VCR by injecting encoded identification signals into the VCR and searching for that signal in the RF output from the VCR. Yet the monitoring of VCRs continues to be a difficult problem.
Changes in the methods of measuring the reception of television or radio programming are required because of a planned change-over from analog to digital broadcasting. In the U.S., the change-over is scheduled to be phased in by the year 2006, as documented in the Federal Communication Commission's Mass Media Docket 87-268, with particular reference to the Fifth Report and Order, FCC 97-116, Apr. 3, 1997 and to the Sixth Report and Order, FCC 97-115, Apr. 3, 1997. Some of the changes, and their respective impacts on approaches used for measuring analog broadcasts, include the following: (1) digital broadcast techniques do not use a vertical blanking interval and, therefore, the program tracking and identifying codes that are written in the vertical blanking interval of analog broadcast signals will not be transmitted; (2) multiple signal formats and associated multiple display formats having, among other features, differing height-to-width ratios and different resolutions are allowed, so that existing video signal correlation methods used with analog broadcasts may essentially be disabled because these methods depend on having the same pictorial feature appear at corresponding places on the measured and reference displays; (3) a broadcaster can transmit as many as six programs (arrayed as a sequence of data packets, where each data packet is labeled as to which of the programs' data is carried therein) within an assigned 6 MHZ frequency band by trading off pictorial resolution for an increase in the number of programs so that (i) digital signal compression methods used to decrease the spectrum space required by a program destroy program identifying codes embedded in an original, high-resolution, program master, and (ii) determining which channel has been tuned by a receiver does not uniquely identify a program being viewed if more than one program is being transmitted in that channel; and, (4) data other than television broadcasting may be co-transmitted in the same channel and, in some cases, it is expected that the other data will be related in some manner to the co-transmitted programming so that a viewer can interact with the TV programming (e.g., to obtain a program guide or detailed information on an advertised product, to automatically switch to a desired program, or to take part in an audience-participation program).
It may be noted that, although projected digital signal compression and transmission methods destroy the types of video codes used in, and suggested for, the prior-generation analog broadcasting approaches, it is expected that less change will be encountered with respect to audio codes. That is, because the audio component of a television broadcast comprises much less information than does the video, there is much less to be gained by applying signal compression methods to audio. Nonetheless, it is expected that various audio compression methods may be employed. These methods include those defined by the Dolby AC-3 or the European MUSICAN standards, or those defined by some yet-to-be-defined standard operable within the relatively open and flexible MPEG arrangement. Although the coding approaches taught in the aforementioned U.S. Pat. No. 5,404,377 are known to survive the Dolby AC-3 and MUSICAN compression methods, compression methods other than Dolby AC-3 and MUSICAN may destroy these codes. Moreover, although the change in technology may obviate the use of some of the codes, such as those described above, other codes (e.g., digital data packet codes telling a receiving site which of several interleaved programs is associated with a given data packet) are expected to be broadcast both with television programming and with any co-transmitted data that are related to, and intended to be used in conjunction with, one or more of the programs.
In addition to changes in transmission equipment and signals, considerable changes are expected in reception equipment. Notable among these are both the use of set top signal converters (generally referred to as set top boxes) allowing a digital broadcast to be viewed on an analog receiver, and a projected convergence of television receivers and computers. In the short term, for example, it is expected that digital receivers, configured as plug-in boards for personal computers, will be used to enable the display of digital television signals on the computers.
Another traditional measurement reflected in television audience reporting has been the determination of who actually viewed the program that was received by the equipment being monitored in a statistically selected monitoring site. A related measurement of interest is the identification of users of on-line services, such as on-line services provided over the Internet. Also, it is clear that measuring the members of an audience in a statistically selected monitoring site who are interactively using a television and/or accessing the Internet, and the information delivery apparatus used to deliver information to the members, will continue to be important.
By far the most commonly used approach in making these measurements is that of interrogation, wherein the viewer and/or Internet user is asked to identify himself or herself as a member of the television audience or as an Internet user. In connection with television viewing, this inquiry is usually done by means of an electronic prompting and data input device (commonly referred to as a Peoplemeter) associated with a monitored receiver in a statistically selected monitoring site. The member identification may also include age, sex, and other demographic data. It is common to store both the demographic data and the tuning data associated with each monitored receiver in the statistically selected monitoring site in store-and-forward equipment located within the monitoring site and to subsequently forward these data to a central office computer via a direct call over the public switched telephone network or via the Internet on a daily basis.
Of particular interest in this area is the teaching of an audience interrogation arrangement disclosed by McKenna, et al., in U.S. Pat. No. 4,816,904. According to this arrangement, a prompting message is displayed on a television screen overlaid on viewer selected programming by mixing the prompting message with the video signal being sent to the display. However, McKenna, et al. do not teach a “tiling” arrangement where the prompting message is displayed on a portion of a display separated from the portion of the display devoted to television picture.
Many arrangements have been proposed in the computer arts for reliably identifying a user so that only selected individuals can secure access to some of the data on a computer or computer system. The most common of such arrangements is that of requiring the user to enter both his or her claimed identity along with a password. Other arrangements have included the use of various biometric techniques, such as image or voice recognition devices. Additionally, it is well known in the audience measurement arts to use computer-based image recognition in order to identify members of a viewing audience. Notable among teachings in this area is that by Lu in U.S. Pat. No. 4,858,000. The teaching of this patent is herein incorporated by reference.